Optical activity of lactones and lactams—I : Conformational dependence of the circular dichroism of 1,3-dioxolan-4-ones

Several optically active 1,3-dioxolan-4-ones were synthesized from corresponding α-hydroxy acids. The Cotton effect sign of these compounds can be explained by Weigang's sector rules. The existence of an equilibrium between envelope and planar conformations of the 5-membered ring was established on the basis of substituent and solvent influence on the CD. It was found that hindered rotation of phenyl group affects the CD of 5-phenyl substituted 1,3-dioxolan-4-ones.